How to Get Rid of Japanese Beetles
Get a quote from exterminators near you
Join the 6,755 people who have received a free, no-obligation quote in the last 30 days
Written by
Japanese beetles are outdoor pests that have voracious appetites for plant leaves and flowers. Native to Japan, these beetles are found throughout much of the United States. While harmless to humans, Japanese beetles are known for destroying home gardens and lawns, leaving brown patches in grass and chewing through plant leaves.
We’ll go over how to treat a Japanese beetle infestation and identify preventative measures you can take to protect your yard. Additionally, we’ll recommend some top pest control companies that can help you get rid of Japanese beetles.
What Are Japanese Beetles?
Adult Japanese beetles can grow up to 1/2 inch long and live between 30 and 45 days, feeding constantly during their life cycle. They’re identified by their metallic blue heads, copper-colored backs, and tan wings. These insects feed together, attacking plants and flowers in groups, so if you see one adult beetle, there is likely a larger infestation.
Females breed underground, tunneling under lawns to lay up to 60 eggs each. Typically, Japanese beetles hatch in droves by the middle of summer, producing grubs that feed on grass roots. As they mature, Japanese beetles ravage home gardens and feed on the leaves of over 300 types of plants.
Japanese beetles are mobile insects, traveling from area to area to find new sources of food. Once they find a plentiful food source, the beetles will breed and lay eggs in their new home.
How to Identify a Japanese Beetle Infestation
Typically, a Japanese beetle infestation can be spotted through close examination of your outdoor plants. While Japanese beetles enjoy many sources of food, they particularly target roses, beans, grapes, and raspberries.
How to Get Rid of Japanese Beetles
Neem oil is a naturally-occurring pesticide found in neem tree seeds. This oil can be applied to your affected plants, where it’s ingested by adult beetles. While non-toxic to plants, it’s important to note that neem oil can impact fish and other aquatic life. It’s also only effective for about three to four days, so you’ll need to reapply frequently.
While it sounds tedious, removing Japanese beetles by hand is one of the quickest and simplest solutions, though it is only likely to be effective for small infestations. Japanese beetles don’t bite or sting, so you can take your time removing them by hand or with thin gloves. The best time for this is typically in the morning when the beetles are sluggish. Once removed, the insects should be placed into a solution of water and dish soap for disposal.
A Japanese beetle trap works by attracting the insects using pheromones or food smells, then killing them or trapping them inside. However, most pest control experts don’t recommend traps for Japanese beetles, since they often attract more beetles than they kill and may make an infestation worse. If you want to try traps, locate them far away from important garden plants.
If you’re experiencing a large Japanese beetle infestation and need a heavy-duty solution, speak to your local garden center about effective pesticides. Many synthetic insecticides are effective against adult Japanese beetles. However, use caution as certain pesticides can harm plants, lawns, and surrounding organisms.
Contact a pest control expert if you’re experiencing a large infestation. A pest control company will evaluate your yard to develop a safe and effective treatment plan and prevent the beetles from coming back. Most professionals use a combination of insecticides and preventative measures.
How to Prevent Japanese Beetles from Returning
Note that you don’t need to eliminate every Japanese beetle or grub from your lawn to protect it. A healthy lawn can sustain five or more grubs per square foot without showing damage. However, if you start to see damage, here are a few ways you can prevent Japanese beetles from overtaking your lawn:
- Use row covers: Row covers are fine nets that surround plants and keep Japanese beetles out. These covers are best used during the peak summer season and come in various sizes to fit your plants’ dimensions.
- Introduce beneficial nematodes: Beneficial nematodes are microscopic worms that infect Japanese beetle grubs with deadly bacteria, preventing them from reaching maturity. Heterorhabditis bacteriophora is the most effective commercially-available nematode variety.
- Target grubs before they grow into beetles: Different synthetic pesticides kill Japanese beetle grubs than kill adult insects, and they must be applied at specific times of year. If you’d prefer biological controls, both milky spore and Bacillus thuringiensis (Bt) are effective against these grubs, but they often take months to work.
- Dry out the turf: Japanese beetle grubs and larvae require moisture to survive, so allowing your grass to dry out can kill them. However, this method risks killing the grass as well, and if there’s rain, it will be ineffective. This method is best used with drought-tolerant, cool-season grass in areas with little to no summer rain.
- Plant geraniums: Japanese beetles are attracted to geraniums, though the plant’s natural chemicals temporarily paralyze the insect, causing them to fall to the ground where they’re more likely to be eaten by predators. Place a container of soapy water beneath the geranium to catch and drown falling beetles.
Our Conclusion
If you don’t want to worry about Japanese beetle control or prevention, the job can be left to professionals. A pest control company will work with you to create an integrated pest management (IPM) solution to eliminate nuisance insects like Japanese beetles and keep them away.We recommend Terminix or Orkin for your pest control needs.
FAQ About How to Get Rid of Japanese Beetles
Are Japanese beetles harmful?
Japanese beetles don’t bite or sting and are considered harmless to pets and humans. However, they do wreak havoc on plants and flowers, gnawing away at fleshy leaves and petals. Their grubs can also kill turfgrass.
What scents deter Japanese beetles?
Some sources claim that particular scents, such as wintergreen or peppermint oil, repel Japanese beetles. However, there is little evidence to back up these claims. You’ll have better results with preventative efforts like keeping your garden plants well-maintained and removing fallen fruit before it can rot.
Why do I have so many Japanese beetles in my yard?
Japanese beetles feed on hundreds of different plants, and your yard may be attractive because of a lack of predators, well-nourished grass for grubs to feed on, and the presence of high-moisture soil.
What are Japanese beetles attracted to?
There are over 300 plants that bring Japanese beetles to your yard, including species like linden, elm, grape, viburnum, and roses.
Do Japanese beetles have any natural predators?
Many wild animals feed on Japanese beetles, particularly bird species like robins and cardinals. Some mammals, such as racoons, moles, and skunks, eat Japanese beetle grubs. However, these mammals may cause damage to your lawn while digging for the insects.
Our Rating Methodology
We back up our pest control recommendations with a detailed rating methodology that we use to objectively score each provider. We review pest control plans, navigate the provider website, speak with customer service representatives by phone and online chat (if available), request quotes, and analyze customer reviews for each provider. We then score the provider against our review standards for plans and services, reputation and customer responses, customer service offerings, workmanship guarantees, financing, and availability to arrive at a final score on a 5-point rating scale.
To share feedback or ask a question about this article, send a note to our Reviews Team at reviews@thisoldhousereviews.com.
